Based on the stories "Mishka's Porridge" and "Druzhok" by Nikolai Nosov.
Two eight-year-old friends, Misha and Kolya, spend a summer day at their dacha without their elders. With them are only little Mayka and their shaggy friend, a faithful and patient dog named Druzhok. That evening, Misha cooks porridge, but even Druzhok refuses to eat it, and when he tries to fry the fish he caught, a fire nearly breaks out in the kitchen. The boys go to bed hungry.
In the morning, Misha and Kolya are traveling home on a steamboat. They secretly carry Druzhok in a suitcase. During the chaos, they take someone else's suitcase. Mishka writes an ad about exchanging suitcases and a missing dog. A pilgrimage of people who have lost their suitcases begins to Mishka's home. By chance, the friends discover they've taken their teacher's (Fyodor Nikitin) suitcase. The boys finally find their Druzhok. But by evening, a whole line has formed outside Misha's apartment: boys from all over the city are bringing dogs in response to his ad...
